Starter for free piston engines



June 10, 1952 F. M. LEWIS ET AL STARTER FOR FREE PISTON ENGINES 2SHEETSSHEET 1 Filed Dec. 6, 1945 Elma/am E FRANK M. LEWI WILLARDA.MURAIN June 10, 1952 F. M. LEWIS ET AL 2,600,251

STARTER FOR FREE PISTON ENGINES 2 SHEETSSHEET 2 Filed Dec. 6, 1945 $3wmQ awe/1M WIS v J FRANK M. LE WILLARD A.MURAIN Patented June 10, 1952STARTER FOR FREE PISTQN ENGINES Frank M. Lewis, Weston, Mass, andWillard v A. Morain, Hamilton, Ohio, assignors, by mesne assignments, toBaldwin-Lima Hamilton Corporation, a corporation of PennsylvaniaApplication December 6, 1945, SeriaLNo. 633,222

(Cl. (Se-l4) 25 Claims.

This invention relates to engine starters, and particularly to suchstarters adapted for use .in connection with internal combustion enginesof the free piston type.

It is necessary in starting such engines to first place the work pistons.at their outer terminal positions and then to force them to their inner.terminal positions with a velocity substantially comparable to that ofthe .compression stroke in normal running of the engine whereby pressureand temperature of sufiicient values may be generated in the combustionchamber to ignite an injected fuel charge after which the .engine willoperate in the regular way.

The object of the present invention is the provision of a simple,noveland .efiicient pneumatic starter of the character described, whichwill meet the mentioned requirements.

The invention is .fully described in the following specification, and apreferred embodiment thereof illustrated in the accompanying drawings,in which:

Figure 1 is a central longitudinal sectional view of one end portion ofafree piston engine with the starting means embodying the inventionassociated therewith; Fig.2 is an enlarged sectional detail ofsaidstarting means; Fig. 3 is a sectional view of a suitable isolationvalve; and Fig. 4 is a somewhat enlarged central vertical sectional viewof one of the governor control valves.

Referring to the drawings, l designates more or less diagrammaticallyone piston set of an internal comubustion free piston engine includingopposed piston sets, each set comprising a working piston '2 operatingin a chamber 3, an

air compressor piston '4 operating in a cylinder 5,

and a direct bounce piston 55 operating in a chamber 1. The piston 4divides the cylinder 55 into an air compressor chamber Bianda-reversebounce chamber 5 The two piston sets are forced outward .by combustionof charges there- 'between in the chamber '3, supplemented by the effectof any pressure in chamber 5", and arereturned to compress chargestherebetween by the force of air compressedinthe bounce chambers l,auxiliary spaces l B, and re-expansion of air trapped in clearance ofcompression .chambersii during outward movements of the pistons. The twodirectbounce auxiliary chambers I0 are con nected'by a pressureequalizer pipe 8 while the chambers so that they will be closed by the.

.art, and .need not.

pistons 6 whenatcrnear the limit .of their out ward strokes. Thesepistons have a sufiiciently loose lit in the outer end of the chambers11 so that when the ports are closed by the pistons the air pressure inthe auxiliary chambers 10 will be permitted to slowly leak around theends ,of the pistons and to enter the free spaces provided between theends of the pistons and the ends of the chambers .1.

The starter means embodying the present in,- vention and which operatesin connection with the above-noted chamber arrangement and connectingpipes includes a body l5 having a high pressure air storage chamber [6(Fig.2) {and a separate limited pressure air charge chamber .11 therein,with the former in connection :With a suitable source of air pressuresuppl through a passage 118. The chamber It has two dis charge outletsl9 and 20 adapted to .be closed by inwardly opening valves 2i and .22,respectively, the stems of which project outward from the chamberthrough a wall thereof and into .acasing part 23 Where they arerespectively engaged by springs 2'4 .and .25 .to normally maintain thevalves seated. The outer end portion .Of a h valvestem is provided witha head 26 receiving the thrust of its spring. The outlet 19 has con,.nection through a line .27 with the pipe .9 con.- .necting the reversebounce chambers 5 of the engine, and in this line 27 is disposed apressure regulator 28 and an outwardly .opening check valve 29, so thatthe air passing through the line 2-1 from the chamber .16 .first has itspressure reduced apredetermined extent by the regulator 28 .and thenpasses through the check valve beforeentering the .pipe 9.

The outlet .20 has a connection through aline 3.0 and through .a'branch.31 with the equalizer pipe 8 -.con ect n the direct bounce chambers,and also has connection through a branch 32 with the charge chamber -11,.with the opening between the branch 32 andchamber continually open. Apressure regulator 3.3 is disposed the line .351, and an outwardlyopening check valve 34 is disposedin the branch :32. The branch 31 hasan outwardlyopeningcheckyalve.35 therein. and also between such valveand the pressure regulator 33 is provided a restricted passage LL36controlled byaneedle valve -37. Ibis thus appar! cut that when the valve22 is open, th 1115b m pressurein the chamber 16 will pass therefromthrough the .line 36, where it is reduced th des red extent by thepressure regulator 39 after which .itdivides, with part passingthrQugh-jhe check valve .34 and throu h the branch3-2 to the charge.chamber I], and part passing u j the valve controlled branch 3| to thepipe {8: flhe pressure regulators 28 and 33 may b 91 a suitableconstruction as well understood in the m r -.b e specifically described.These regulators, as is common, are manually controllable to regulatethe pressure reduction effected thereby.

Each reverse bounce chamber 5 at its outer end relative to the piston 4is provided with a plurality of pressure relief ports 49 (one only beingshown), and each is normally closed by a valve 4|, the stem of whichprojects into a cylinder 42 and attaches to a piston 43 therein. Aspring 44 acts against the piston 43 to normally retain the valve closedand pressure is admitted to the outer end of the cylinder 42 through aline 45 to act against the piston 43 in opposition to the pressure ofthe spring 44 and efiect an inward opening of the valve 4|. Between theport 49 and cylinder 42 are provided a plurality of exhaust openings 46for the release of the air pressure to the atmosphere from the reversebounce chamber 5 when the valve is open. Pressure is admitted to theline 45 from the charge chamber H through a line 41. The inner end ofthe line 41, or that opening into the chamber I1, is controlled by avalve 48, the stem of which projects through and above the top wall ofsuch chamber where it is acted on by a spring 49 to hold the valveclosed. The spring seats against a head or enlargement 58 on the outerend of the valve stem.

The admission of high pressure air to the chamber Hi from the line I8 iscontrolled by a valve 5|, the stem of which projects outwardly from thechamber wall through suitable guides and is acted on by a spring 52 tonormally maintain the valve seated. The stems of the valves 48 and 5|are disposed, in the present instance, in parallel relation and adjacentto each other with the stem of the latter valve projecting a greaterdistance from the body I5 than the other and provided at its outer endwith a head or shoulder 53. The stems of the valves 2| and 22 are alsodisposed in rather close parallel relation with the stem of the valve 2|projecting a less distance from the casing of the body l5 than theother. This relative positioning and length of the valves 2|, 22, 48 and5| are to facilitate operation of the valves by the control meanshereinafter described.

A pressure relief passage 55 communicates with the pressure line 4'!adjacent to its point of connection with the chamber l1 and this line iscontrolled by a normally open valve 55 and at the outer side of suchvalve by a needle valve 51. The valve 56 projects from a plunger 58operating in a cylinder 59 and is normally held open by the pressure ofa spring 68 against such plunger. The cylinder 59, at the outer side ofthe plunger 58, has communication through line 6| with pipe 8 whichconnects the direct bounce chambers, so that when a suficient pressureis present in the line 8 to overcome the compression of the spring 68,such pressure will move the plunger 58 and hold the valve 56 closed ifvalve 62 is in open position as later described. The line 6| has anormally closed check valve 62 therein which opens outwardly from thecylinder 59 and is normally held closed by a spring 63. This valve has astem 64 projecting upwardly to exposed position through the portion 65of the body I5 in which it is mounted, and, in the present instance, itis parallel to the stems of the valves 2|, 22, 48 and 5|. The purpose ofthe valve 62 will be later described.

The control means for the valves 2|, 22, 48, 5| and 62 will now bedescribed. Mounted in the present instance on top of the body l5 nearits left end is a stationary guide sector 19 with which the handoperated catch H on a hand lever 12 is adapted to engage to hold thelever in different positions of adjustment relative to the sector.

In the present instance, the sector has notches a, b and c with whichthe catch engages to hold the lever, respectively, in off, charge andstart positions. The lever i mounted on a shaft 13 for rocking movementslengthwise of the sector, and this shaft also carries an independentlyrockable arm 1'4, the outer end of which is provided with an arcuatesurface 15 concentric to the shaft axis and having a stop ldnear itsrear or left hand end. A spring pressed pawl TI on the lever 12 rides atone end on the surface 15 and at its other end on an inner surface ofthe sector 10. This latter surface is divided lengthwise thereof intotwo arcuate surfaces at and c that are concentric to the lever axis andare connected by a cam portion 1. When the lever 12 is bein moved fromoff to near its charge position, the outer end of the pawl i1 will rideagainst the surface at and cause the arm 14 to move therewith due toengagement of the inner end of the pawl with the shoulder 16. When thelever has nearly reached said charge position, the outer end of the pawlH will engage and pass over the cam surface 1, thereby moving the pawlto disengaged position relative to the shoulder 16 and maintaining suchposition during movement of the pawl along the surface 6.

Projecting rearwardly from the inner end of the arm 14 away from itsrocking axis is an arm 19 that is pivotally connected at its outer endto a plunger 88 by a link 8|, such arm and link forming a toggleconnection between the inner end of the arm 14 and the plunger, withsuch connection upwardly broken or raised from straight or dead centerposition when the arm 14 is at the limit of its movement to the right.The plunger 88 works in a cylinder 82 and receives the thrust of acoiled compression spring 83 in said cylinder acting inwardly on thetoggle link members 19, 8|. A rod 84 projects from the pivotalconnecting point 85 of the members 19 and 8|, substantially at rightangles to the line of movement of the plunger 88, and connects at itsouter end to a plunger 86 operating in a cylinder 8?. The outer end ofthis cylinder relative to the rod 84 forms an air pressure chamber thathas communication through a line 88 with the pipe 8 connecting thedirect bounce chambers of the engine. It is apparent that air pressurein the pipe 8 acts through the line 88 against the piston 86 and tendsto keep the connection 19, 8|, in its upwardly broken position. When thearm M has been moved a short distance to the left from the "oif positionshown, by a counterclockwise movement of the lever i2 from its offposition, the toggle connection 79, 8| will have lowered an extentsufllcient to move the pivot 85 across and below dead center position sothat the plunger 86 will then be quickly moved downward in its cylinder81 by the downward breaking movement of the toggle connection and underthe pressure of the spring 83, thus causing the arm 14 to quickly moveindependently to the left of the lever 12 to its stop position againstthe part 18. It will be understood that at this stage in a startingoperation there is practically no pressure in the direct bounce chambersI and consequently in the line 8 with which the cylinder 81 isconnected. It will also be understood that when the direct bouncepressure has increased sufficiently in the chamber 81 to overcome theenter the pressure responsive means I I8 and open valve II9, therebyventing the bounce pressure chamber I to the atmosphere.

The reverse bounce pressure governor B has a line I25 in connection withthe reverse bounce chambers a line I26 in connection with a highpressure air supply line I21, a fluid pressure line I28, at present inconnection with the fuel feed line of the engine, and a normally closedvent line I29. Line I2 6 acts only during running of the engine as partof the governing function and forms no part of the starter mechanism. Acontrol valve I35 is moved to the right by pressure in line I whenpressure in spring I3I is relieved by moving control lever I32 to stopposition. Pressure in line I25 acts to expand a-bellows at the left ofvalve I forcing the latter to the right. This movement of valve I30admits pressure from line I28 to pressure responsive means I33, whichcauses opening of relief valve I34 to vent the pressure in reversebounce pressure line I25. Such venting relieves the pressure fromresponsive means I05 in governor A and permits movement of lever III! byspring I09 to effect a venting of the direct bounce chambers I throughthe lines H3 and 8.

It is thus seen that when the engine is stopped, the governor B acts torelieve the reverse bounce pressure and that this in turn acts throughgovernor A to vent the direct bounce chamber pressure. The invention isdisclosed in conjunction with these governors since it has beenconstructed in this manner and the disclosure is thus of preferred form.However, any equivalent pressure sensitive valve arrangement may beused.

In order to make the starting means operative in connection with anengine having such direct and reverse bounce venting means, it isdesirable to have an operative connection between the starting andventing means, whereby the two governors are blocked off from therespective direct and reverse bounce chambers during the startingprocess and are opened thereto as the unit achieves running equilibrium.

To accomplish this the direct bounce pressure line II3 to governor A andthe reverse bounce pres-sure line I25 to governor B are each providedwith an isolating or'block-oif valve I38, shown in detail in Fig. 3.Each of these valves moves across the respective pressure line I25 and II3 and carries a piston I39 operating in a cylinder I413. The valve isnormally held open by a spring I4I and is closed by pressure against theouter side of the piston supplied through a line I42. This line connectsboth valve cylinders and is supplied with pressure from the highpressure air line I8 through a branch I43 extending through a part ofthe starter body structure I5 (Fig. 2).

A valve I44 is acted on by a spring I45 to normally close said branchwithin said structure and the valve is unseated by movement of a bellcrank lever I46. This lever is fulcrumed at I41 and has one arm engagingthe valve stem and its other arm engaging a rod I48 attached ,to andoperable by movements of the upright arm of the lever '92. Thisattachment is such that upon a rearward or counterclockwise movement ofsaid lever under the action of the spring 45, and when the rod 90 ismoved to the left, the lever I46 is moved to lift the valve I44 from itsseat and open the line I43. The rod I48 also controls a vent valve I49to close a vent passage I50 when the rod is moved to the left and toopen such passage when the rod is in its right hand position. Thepassage I50 leads to the atmosphere from the line I-43 at a side of thevalve I40 opposed to the air pressure supply source. The vent I50 is sorestricted by the throttling needle valve I5I as to retard theengagement of the governors A and B until after the unit achievesrunning equilibrium.

A brief description of the operation of the starter means is as follows:Presuming that the pressures in the bounce chambers I and connectedauxiliary chambers I0 have been vented through the relief passage ingovernor A when the engine was last stopped, the operator sets the fuelfeed for a running condition slightly greater than idling and also setsthe control I32 for the governor B so as to tension the spring I3I toprovide for proper reverse bounce effect which will be achieved by thestarting conditions. This moves the valve I33 to the left permitting aclosing of the relief valve I34 so that the vent from the reverse bouncechambers is closed. However, the vent from the chambers I and I0 isstill open through the governor A. The operator then moves the startercontrol lever I2 from the off" to the charge position, that is, from thea to the b notches in the sector III. The rocker arm I4 moves with thelever in this movement due to the engagement of the pawl 11 with saidarm until the pivot of'the toggle I9, 8|, has been moved past deadcenter position, whereupon the spring 83 will act to quickly move therocker arm to the limit of its rearward or counterclockwise movement.This movement of the rocker arm closes valve 48 and opens the valve 5|,the latter admitting high pressure air to the chamber I6 from lines I8and I21. At the same time, when the lever I2 is near its chargeposition, its arm will engage the head 25 andopen the valve 2 I. Thispermits high pressure air to pass from chamber it through the valvecontrolled line 2'! to the reverse bounce chambers 5 to force the enginepistons to the limit of their outward movements. The movement of thecontrol lever I2 to charge position moves the pawl TI to releasedposition relative to the shoulder I6 on the arm 14 due to one end of thepawl riding over the cam portion ,1 of the sector '10. The lever may nowbe moved from charge to start position or from the notch b to notch c inthe sector ID. This movement causes the lever arm 95 to further open thevalve '2! and also to engage the head 26 on the valve 22 and effect anopening of such valve. Thereupon the compressed air from chamber I6flows through the pressure regulator 33 and non-return check valve 34 tothe charge chamber II, the valves 48 and 56 being now closed, and alsoflows through lines 30, 3| and 8 to build up pressure in the directbounce reservoirs I8. This pressure also acts through line 88 on piston85. Chamber II should charge to the full pressure permitted by thereducer valve before chambers I5 reach their charge pressures, and it isthe function of valve 31 to produce the necessary restriction in line'3I. When the pressure in chambers I0 reaches a certain predeterminedvalue, piston 86 overcomes the effect of spring 83 and snaps the toggle19, 8| back to its initial raised position, and consequently moves therocker arm I4 quickly to its forward initial position. Thissimultaneously opens valve 48 and closes valve 5I, causing the highpressure air to be delivered from the chamber II through line 41 topiston 43 and opening vent valves 4| in reverse bounce chambers 5 and atthe same time shutting off the high pressure supply to chamber 5pressure of the spring 83, the plunger 86 will be moved outward to causean outward movement of the center pin 85 past dead center position,causing the sprin 83 to then act to quickly return the rocker arm 14 toits right end position, as shown in Fig. 2 of the drawings.

The rocker arm 74 has a rod 90 pivoted thereto and projecting forwardlytherefrom, or to the right, and through a guide bracket 9| rising fromthe body [5. The free end of this rod bears against the upwardly andforwardly extending arm of a bell-crank lever 92 that is fulcrumed onthe body [5, while the other arm of such lever extends rearwardly andupwardly and bears upwardly against the head 59 on the stem of the valve48 and in opposition to the spring 49. When the rocker arm 14 is in itsright end position, the rod 90 acts on the lever 92 to hold the valve 48raised in its open position and during the initial rearward movement ofthe arm 14 the opening pressure of the lever 92 on the valve isreleased, thus permitting a closing of such valve.

A bell-crank lever 93 is fulcrumed to the bracket 9i and has ahorizontally extending arm adapted to engage the stem head 53 of thevalve 5|, so as to move such valve from closed position when the leverarm is moved upward. The other arm of said lever extends downwardly andhas an aperture therein through which the rod 90 extends. rocker arm 14and when it is near the limit of such movement, a shoulder 94 on the rod90 engages the downwardly projecting arm of the lever 93 and moves thelever to effect an unseating of the valve 5|, thus admitting air from ahigh pressure air supply in I21 to the pressure chamber Hi. Thisunseating action of the valve 5| is rapid due to the rapid movement ofthe rocker arm 14 under the action of the spring 83.

The control lever i2 has an arm 95 projecting to the right from itsinner end and provided with apertures through which the stems of thevalves 2| and 22 project. During the movement of the control lever 12from its ofi to charge position, arm 95 will engage first the head 26 ofthe valve 21 and cause an opening of such valve to permit the pressurein the chamber IE to pass through the line 27 and valves 28, 29 thereinto the reverse bounce connection 9, and thence to the two reverse bouncechambers 5 to impart outward stroke movements to the piston sets. Thecontrol lever I2 is retained in the "charge position until the pistons 6have reached their extreme outer position, the piston heads closing ofiports i i and continuing until they are in contact with or just miss theends of the cylinders I.

The control lever 72 is then moved from notch 12 to c on the sector 18.During this movement, the arm 95 will act on the head 26 of the valve 22and force said valve open against the compression of its spring 25, thuspermitting compressed air to pass from the storage chamber i6 into theline 3!! and through branch 32 to chamber H and through branch 31 to thedirect bounce chamber connection 8 so as to build up a pressure in suchconnection and in the chambers to sumcient to force the engine pistonsto their inward positions at the required velocity.

When the pressure in chambers has built up to a predetermined value,this acts through line 88 against the plunger 86 to move the operatingconnection 1 9, 8 I of the rocker arm upwardly past dead center positionso as to permit the spring 83 to act to quickly throw said arm to itsright hand position at which time valve is permitted During a movementto the left of the 6 to close and valve 43 is caused to open. The valve43 is held open so that the pressure in the chamber 1'! is admittedthrough the lines 41 and to the cylinder 42 to act against the pistons43 therein to open the valves 4| and relieve any pressure in the reversebounce chamber 5 which might oppose inward movement of the pistons.

A rod [68 extends from the control lever 12 near the inner end to alever Nil to which it pivotally connects, such lever being fulcrumed toa bracket [82 rising from the body extension 65, and the lower end ofsuch lever is provided with a cam foot Hi3 acting against the outer endof the stem 64 of the valve 62. This arrangement is such that when thelever 72 is in its ofif position, the valve G2 is closed, and when thecontrol lever is moved away from such position, the cam i 83 actsagainst the valve stem to open the valve, thus permitting the pressurein the line 6| to act against the plunger 58. It will be understood thatafter starting and during a running of the engine, the pressure in theline 6! fluctuates with the pressure in the direct bounce chambers sothat if the connection of this line with the cylinder 59 were not cutoil during such running of the engine, the valve would have a flutteringaction. It is for this reason that the starting mechanism is equippedwith means for opening the line 6! to the chamber 53 during a startingoperation and to close such connection when starting has been effected.

Before outward movement of the engine pistons i, effected by admissionof air pressure to the reverse bounce chambers 5 of the engine, thedirect bounce chambers 7 are vented, in the present instance, by meansoperated automatically by the starter mechanism in conjunction withpressure control governors for the engine. Such governors are shown andclaimed in Patent No. 2,435,970, by Frank M. Lewis, one of theapplicants herein. These governors are illustrated in Fig. 1 anddesignated A and B," the former controlling the direct bounce chamberpressure and the latter the reverse bounce chamber pressure. Theoperation of these governors need only be described suiiiciently in thepresent case to make their operation in connection with the startingmechanism clear.

Governor A includes four pressure responsive means I65, H33, id! andI08, together with a spring its acting on a lever lie to hold it in aclosed position when the engine is operating properly. These bellowshave connection, respectively, through lines Ill, H2, H3 and H4 with thecompressor chambers 5 the reverse bounce chambers 5 the direct bouncechambers 1 and the scavenging receiver H5. The line H3 connects with thedirect bounce chamber line 8 through a pressure controlled mechanismoperated by the lever Iii whereby a lowering of the right end of suchlever will cause the direct bounce pressure to be increased by theadmission of air pressure thereto, and a raising of such end of thelever will cause a venting of the bounce chamber pressure.

This venting of the bounce chamber pressure is accomplishedautomatically as follows: When the engine is stopped the reverse bouncepressure is vented through governor B as hereinafter described, thusrelieving pressure in the pressure responsive means I06 of governor A,which causes an unbalancing of the pressures against lever H0 andpermits the spring 199 to force the right end of the lever upward. Thisraises valve I "Send permits pressure from fuel oil supply line H1 toI16. The air in the direct bounce reservoirs It must leak around thecircumferential clearance of the bounce piston 6; at its extremeoutward. position. before it can get behind the. piston and do work.While this relatively slowprocess is taking place, the air in. thereverse bounce chambers 5 will have dropped approximately to atmosphericpressure due to opening the valve 4|. The pistons then move totheirinner stroke positions, compressing the fuel charge for com.- bustion.During this stroke the vent valves 4| are. still held open, since theescape of air from behind the valves is prevented by valve 59. Whenthedirect bounce pressure has dropped. to some predetermined pressure,spring 60 over-- comes the gas load on the piston 59; allowing valve 56to open. and then. the air: holding, the: vent valves open bleeds to theatmosphere. The drop in pressure: behind the vent valves will begoverned by the. opening. of. needle valve 51 and the volume of thechamber I'I'. These quantities will be so: regulated. that the valvesprings '44 in connection with the valves: will not. overcome the air;pressure and close-the vent valve 4 I until some time during the outwardpower strokes; of the engine; pistons, after the proper air quantity hasbeen taken intothe reverse bounce chambers 5 to effect an energybalanceforthe stroke. Starting having; been effected in this manner,control lever I2 may then be returned at leisure to its 01f position:and its latch engaged with the sector notch a. The movement of the lever92 valve 48;. which movement occurs during, the

rearward or left hand stroke of. the starter control member I5, movesthe rod I48 attached to such. lever, causing a rocking of the lever I49and an: opening of the valve I44 in the high. pressure airline I49, thuspermitting such pressure to. act through theline I42 on the pistons: I39and move the: block-off valves I38 to close the line H3 of governorA andline of governor B, thus preventing the venting of both the directbounce and reversebounce chambers. This movement oi therod I48 also:moves the vent valve I49 to closed position to prevent any venting of.the lines; I42, I43. The return of. the control member I5 to: its normalposition permits closing of the valve I44: and moves the vent valve I-49to position to: vent the passage I59, thus relieving the pressureholding the block-off valves I38? closed and permitting'them. to openunder the pressures of their springs. The governors A and. B. are thusagain. rendered operative in connection. with the operation of: theengine.

We wish it understood that our invention is not, limited. to anyspecific. construction, arrangement on form of. the parts,v as it. iscapable of numerousv modifications and: changes without.departingfromthespiritiof the-claims.

Having thus: described our invention, what we claim. as; new, and desireto secure by United States. Letters Patentisr 1 A. starter for an.internal combustion engine of: the free piston type? having a. directbounce chamber, compression inwhich tends to move the engine piston inthe direction of'its. compression stroke, and a reverse. bounce chamber;compression in which tends tomove the piston in thedis rection of itsoutward stroke, comprising asource of gas under pressure, means operableto. connect said source first with the reverse bounce chamber and thenwith the direct bounce chamber to move said pistonfirstonits workingstroke and then on a compression stroke, said means operating to 10vent. said reverse bounce chamber prior to-movementof said piston on. acompression stroke and automatic means for cutting off the sourceconnection to both said chambers when a predeter' mined pressure hasbeen obtained in the direct bounce chamber.

2. An arrangement as called for in claim I, together with means operableto vent said. direct bounce and reverse bounce chambers when the engineis at rest, and means operable by the-first mentioned means to rendersaid vent means inoperable during predetermined portions of a startingoperation.

3. A. starter for an. internal combustion engineof thefree piston. typehaving a direct bounce chamber, compression. in which. tends to move theengine piston. in the, direction of its compression stroke, anda reversebounce. chamber, compression in which tends tomove the piston in. the(11 rection of its outward stroke, comprising a source of gas under.pressure. manually operable means to connect said source first with thereverse bounce chamber and then with the direct bounce chamben, anexhaust valve for the reverse bounce chamber, and automatic meansresponsive to a: predetermined direct bounce chamber pressure foropening said exhaust valve after the direct bounce chamberis connectedtosaid source.

4. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, anda reversebounce chamber, compression in. which tends to move the piston. in thedirection or its outward stroke, comprising a source of gas underpressure, manually operable means to connect said source first with. thereverse bounce chamber and then with the. direct bounce chamber, anexhaust valve for the reverse bounce: chamber,v and automatic meansresponsive. to. predetermined pressure in the direct. bounce chamber foropening said exhaust valve and for cutting: ofi the connections to saidsource.

5. A starter for an internal combustion. engine of the free piston.type. having a direct bounce chamber, compression in which tends to movethe engine piston in the direction of its compression stroke, and areverse bounce chamber, compression in which tends to move the piston inthe direction ofits outward stroke, comprising a source of gas: underpressure, two valves for connecting said source with said chambersrespectively, and manually operable means movable in one direc tion. tofirst: open. the valve to the reverse: bounce chamber: and further onits movement to open the valve to the direct. bounce chamber, an exhaustvalve for the reverse bounce chamber, and means operable by pressureconnected to the. direct; bounce chamberto. open said exhaust valve.

6.. A. starter for an internal. combustion engine of, the free pistontype having a direct bounce chamber, compression in which tends tomovethe engine piston in the direction of its compression stroke; and: areverse bounce chamber, compression. in which tends to move the pistonin: the direction of its outward stroke, comprisingan auxiliary chamberconnected by a leakage passage tio the direct bounce chamber when: theengine pistonisatt theen'dof its working stroke and by open ports whenthe piston has moved a short distance on its compression stroke, asourceof gas under pressure, a manually operable valveforconnectingsaid-source with said reverse bounce chamber, a manuallyoperable valvefor connecting said source with said auxiliary chamber, anexhaust valve for the reverse bounce chamber, and means operable bypressure in said auxiliary chamber to open said exhaust valve.

7. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, and a reversebounce chamber, compression in which tends to move the piston in thedirection of its outward stroke, comprising a source of gas underpressure, means providing a storage chamber for gas under pressure,manually operable means for connecting said source to said storagechamber and connecting said storage chamber to said reverse bouncechamber, manually operable means to thereafter connect said storagechamber to said direct bounce chamber, means to vent said reverse bouncechamber after a predetermined pressure has been attained in said directbounce chamber and automatic means responsive to direct bounce chamberpressure to break the connection between said source and said storagechamber.

8. An arrangement as called for in claim 7, together with vent meansoperable to vent both said bounce and reverse bounce chambers when theengine is stopped, and means for rendering said vent means inoperableduring predetermined portions of a starting operation.

9. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, and a reversebounce chamber, compression in which tends to move the piston in thedirection of its outward stroke, comprising a source of gas underpressure, means providing a storage chamber for gas under pressure,manually operable means for connecting said source to said storagechamber and connecting said storage chamber to said reverse bouncechamber, manually operable means to thereafter connect said storagechamber to said direct bounce chamber, an exhaust valve for the reversebounce chamber, and automatic means operable by pressure connected tosaid direct bounce chamber to break the connection from said source tosaid storage chamber and to open said exhaust valve.

10. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, and a reversebounce chamber, compression in which tends to move the piston in thedirection of its outward stroke, comprising a source of gas underpressure, manually operable means to connect said source first with thereverse bounce chamber and then with the direct bounce chamber, anexhaust valve for the reverse bounce chamber, automatic means responsiveto direct bounce chamber pressure for opening said exhaust valve afterthe direct bounce chamber is connected to said source, and automaticmeans to close said exhaust valve after the piston starts on its nextworking stroke.

11. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, means operableto vent said bounce chamher when the engine is stopped, and a reversebounce chamber, compression in which tends to move the piston in thedirection of its outward stroke, comprising a source of gas underpressure, manually operable means to connect said source first with thereverse bounce chamber and then with the direct bounce chamber, anexhaust valve for the reverse bounce chamber, automatic means responsiveto direct bounce chamber pressure for opening said exhaust valve afterthe direct bounce chamber is connected to said source, and automaticmeans to close said exhaust valve after the piston starts on its nextworking stroke, and means operable by said manually operable means torender said vent means inoperable during admission of the gas pressureto said reverse bounce and direct bounce chambers during a startingoperation.

12. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, and a reversebounce chamber, compression in which tends to move the piston in thedirection of its outward stroke, comprising a source of gas underpressure, manually operable means to connect said source first with thereverse bounce chamber and then with the direct bounce chamber, anexhaust valve for the reverse bounce chamber, automatic means responsiveto direct bounce chamber pressure for opening said valve, automaticmeans to close said exhaust valve after the completion of thecompression stroke, and means for adjusting the last said means so thata predetermined portion of the next working stroke elapses before theexhaust valve closes.

13. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, and a reversebounce chamber, compression in which tends to move the piston in thedirection of its outward stroke, comprising a source of gas underpressure, manually operable means to connect said source first with thereverse bounce chamber and then with the direct bounce chamber, anexhaust valve for the reverse bounce chamber, and automatic means foropening said exhaust valve after the direct bounce chamber is connectedto said source, said automatic means comprising a toggle, connections tosaid manually operable means for breaking the toggle in one direction, aspring for holding the toggle broken, a piston connected to said toggle,a cylinder around said piston, and means providing a passage from thedirect bounce chamber to said cylinder to straighten the toggle when apredetermined pressure is present in the direct bounce chamber.

14. A starter for an internal combustion engine of the free piston typehaving a direct bounce chamber, compression in which tends to move theengine piston in the direction of its compression stroke, and a reversebounce chamber, compression in which tends to move the piston in thedirection of its outward stroke, comprising aconnectionsto said:manually opemblemeansior breaking the. tog le in one direction,, aspring, for: holding the. toggle broken, a piston connected. to;

the. toggle, a. cylinder around said: piston, and means providing; apassagefromzthe direct bounce chamber tosaidcylinder'to; straighten the.toggle when, a predeterminedpressure is. present; in the bounce.chamber:

.15. A starter. for an internal; combustion ens gineof the free; pistontype having; a direct bounce chamber, compression in which, tendsto.

movev the; engine piston. in the. direction. of. its

compression stroke, anda reverse bounce chamber, compressionin whichtends. to move the piston in. the direction ofits outward strokercomeprising a-.sourc.e.of gas under. pressure, manually operable means. toconnect saidsourceflrst with the. reverse bounce chamber and then withthe direct bounce chamber, an exhaust, valve, for: the

reversebounce chamber, and automatic means 16. An arrangement, as calledfor in claim 15,

together with means normally standing open and responsive to pressure insaid direct. bounce chamber to close said leak passage, and meansnormally rendering said responsive means. in-

operative and' manually operable to rendersaid responsive meansoperable.

1.7. An. apparatus for. controlling starting of an internal combustionfree piston machine having an air compressor piston. subject on one sideto air in. an air compressing chamber and on the i oppositeside to airin a reverse; bounce chamber, a rigidly connected power piston operableby products of combustion from compression ignition in a power chamberto actuate-said compressor piston on an. air compression stroke, and

direct bounce air cushion means for actuating said. piston. on. an airintake stroke and to provide compression ignition, said apparatuscomprising reverse bounce supply means for supplying fluid underpressure. to said reverse bounce chamber for. moving said pistons. on anair compression stroke to a starting position, direct bounce supplymeans operable-uponmovement or said pistons to said starting position tosupply fluid under pressure to said air cushion means, vent valve meansfor releasing fluid under pressure from, said reverse. bounce chamber torender said fluid under pressure in said cushion means efi'ective tomove said pistons on said intake stroke to provide. compressionignition, and sequence means operable upon a chosen increase in pressurein said cushion means to effect operation of said reverse bounce supplymeans to out off supply of fluid under pressure to said reverse bouncechamber and to also eiiect operation of said vent valve means to releasefluid under pressure from said reverse bounce chamber.

18. An apparatus for controllingstarting of an internal combustion freepiston machine having an air compressor piston subject on one side toair in. an air compressing chamber and on the opposite side to air in areverse bounce chamber, a rigidly connected power piston operable byproducts of combustionfrom.compression ignit o in a. power chamber toactuate said compressor piston. on an.- air compression.- s roke;, and:d rect bounce air cushion. means for actuating; said. 915 ton an an airintake: stroke and to provideecoma pression ignition. said: apparatus.comprising reverse. bounce supply means for supplying; fluid: underpressure to said. reverse bounce; chamber for moving said pistons on anair compression; stroke to-a startin p sition, dircctbounce 8119.13. 3means operableupon, movement of; said pistons to;v said. startingposition to supply; fluid under pressure to. said. air. cushion; means,vent; val means for releasing fluid und r: pressure from: said; reversebounce chamber-to. render. said fluid under. pressure. saidcushion meanseffective; to; move said. pistons on. saidv intake. stroke to nrode;compression. ignition. and. soqu nos; means. op rable. upon a, chosenincrease pr sure n said cushion. means to effect opera ion. of: said.direct. bounce supply means and. reverse. bounce supply means tov cutonthe. supplyof; fluid under pressure to, respectively: said cushion meanssaid reverse bounce chamber and to also eiiect operation of said ventvalve, means.

19. An apparatus for controlling starting of an, internal combustionfree piston machine; having; an air compressor piston subject on one.side toair in an air compressing chamber and onthe-opposite side to, airin a reverse. bounce chamber, arigidly connected power piston operableby prod nets of combustion from compression. ignition in a power chamberto actuate said compressor piston on an air compression stroke, and.direct bounce air cushion means for actuating said. pis ton on anv airintake stroke and to provide come pression ignition, said apparatuscomprisin reversev bounce supply means for supplying fluid. underpressure. to said reverse. bounce chamber for moving said pistons on anair compression. stroke to a starting position. directb unce supply mens op r ble. upon movement of sa d. pi tons to said starting positionto; supply fluid under pr ur t said air cushion. me ns. vent valve meansfor releasing fluid under pressure from said reverse bounce chamber torender said fluid: under pressure in said cushion means effective. tomove said pistons. on said. intake stroke, to pro.- vide compressionignition, sequence means, operable upon a chosen. increase in pressure.in said cushion means to effect operation of said direct bounce supplymeans and reverse bounce supply means to cut oil the supply of fluidunder pressure to, respectively, said cushion means and said reversebounce chamber and to also efl'ect operat tion of said vent valve.means, and means operle upon a chosen reduction inpressure of. fluid insaid. cushion means to. effect operation or said.

vent valve means to terminate release. oi fluid.

under pressure from said reverse bouncechamber.

20. An, apparatus forcontrolling starting of, an internal combustionfree piston machine. having; n air compressing pist n subj cton ppositesides tov pressure ofair in air compressing a d reverse bounce chambers,respectively, a rigidly connected. power piston. for. moving: saidcorn-- pressing piston inthe direction against air insaid air comressing chamber; and direct bounce fluid pressure cushion. means formovin said piston. in the oppos te direction, said apparatus" comprisingfirst valve means for supplyingfluid under pressure t a d; reversebouncechamberfor moving said pistons to a chosen position in the; firstnamed, direction, second. valve means. for supplying fluid underpressure to. said cushion means,v vent. valve means: for ventin thefluid under press re from; said. reverse bouncechanc ber, and means forefiecting operation of said vent valve means upon a chosen increase inpressure in said cushion means.

21. An apparatus for controlling starting of an internal combustion freepiston machine having an air compressing piston subject on oppositesides to pressure of air in air compressing and reverse bounce chambersrespectively, a rigidly connected power piston for moving saidcompressing piston in the direction against air in said air compressingchamber, and direct bounce fluid pressure cushion means for moving saidpiston in the opposite direction, said apparatus comprising valve meansfor supplying fluid under pressure to said reverse bounce chamber and tosaid cushion means, means for delaying supply of fluid under pressure tosaid cushion means with respect to supply of fluid under pressure tosaid reverse bounce chamber, means for cutting oil said supply of fluidunder pressure to and for bottling up the fluid pressure in said cushionmeans, vent valve means for venting the fluid under pressure from saidreverse bounce chamber, and means responsive to a certain increase inpressure in said cushion means to effect operation of said vent valvemeans.

22. An apparatus for controlling starting of an internal combustion freepiston machine having an air compressing piston subject on oppositesides to pressure of air in air compressing and reverse bounce chambers,respectively, a rigidly connected power piston for moving saidcompressing piston in the direction against air in said air compressingchamber, and direct bounce fluid pressure cushion means for moving saidpiston in the opposite direction, said apparatus comprising means forsupplying fluid under pressure to said reverse bounce chamber to movesaid pistons to a chosen positiondn the first named direction, means forlimiting to a chosen degree the pressure of fluid supplied to saidreverse bounce chamber, means for supplying fluid under pressure to saidcushion means, means for limiting to a chosen higher degree the pressureof fluid supplied to said cushion means, vent valve means for ventingfluid under pressure from said reverse bounce chamber, and meansresponsive to a chosen increase in pressure in said cushion means toeffect operation of said vent valve means.

23. An apparatus for controlling starting of an internal combustion freepiston machine having an air compressing piston subject on oppositesides to pressure of air in air compressing and reverse bounce chambersrespectively, a rigidly connected power piston for moving saidcompressing piston in the direction against air in said air compressingchamber, and direct bounce fluid pressure cushion means for moving saidpiston in the opposite direction, said apparatus comprising a firstvalve means for supplying fluid under pressure to said reverse bouncechamber for moving said pistons to a chosen position in the first nameddirection, fluid pressure operable vent valve means for releasing fluidunder pressure from said reverse bounce chamber, a feed valve deviceoperable upon supply of fluid under pressure to a first communication tosupply fluid at a reduced pressure from said communication to saidcushion means and to another communication, choke and check valve meansin the fluid supply communication to said cushion means, a check valvefor preventing reverse flow of fluid under pressure from said othercommunication, a second valve means for supplying fluid under 16pressure to said first communication, a third valve means for openingsaid other communication to said vent valve means, and means foreffecting sequential operation of said first, second and third valvemeans in the order named.

24. An apparatus for controlling starting of an internal combustion freepiston machine having an air compressing piston subject on oppositesides to pressure of air in air compressing and reverse bounce chambersrespectivey, a rigidly connected power piston for moving saidcompressing piston in the direction against air in said air compressingchamber, and direct bounce fluid pressure cushion means for moving saidpiston in the opposite direction, said apparatus comprising a firstvalve means for supplying fluid under pressure to said reverse bouncechamber for moving said pistons to a chosen position in the flrst nameddirection, a second valve means for supplying fluid under pressure tosaid cushion means, means for delaying operation of said second valvemeans with respect to operation of said first valve means, vent valvemeans for opening a vent from said reverse bounce chamber for releasingfluid under pressure therefrom to render said pistons movable bypressure of fluid in said cushion means, means responsive to a chosenincrease in pressure in said cushion means to effect operation of saidvent valve means to open said vent, and means operable in response to areduction in pressure in said cushion means to effect operation of saidvent valve means to close said vent.

25. An apparatus for controlling starting of an internal combustion freepiston machine having an air compressing piston subject on oppositesides to pressure of air in air compressing and reverse bounce chambers,respectively, a rigidly connected power piston for moving saidcompressing piston in the direction against air in said air compressingchamber, and direct bounce fluid pressure cushion means for moving saidpiston in the opposite direction, said apparatus comprising first valvemeans for supplying fluid under pressure to said reverse bounce chamber,second valve means for supplying fluid under pressure to said cushionmeans, vent valve means operable by fluid under pressure to open a fluidpressure vent from said reverse bounce chamber for releasing fluidtherefrom to render said pistons movable by pressure of fluid in saidcushion means, exhaust valve means for releasing fluid under pressurefrom said vent valve means to efiect operation thereof to close saidvent, and means for delaying operation of said second valve means withrespect to operation of said first valve means and for. effecting firstsupply of fluid under pressure to said vent valve means and thenoperation of exhaust valve means, subsequent to operation of said secondvalve means.

FRANK M. LEWIS. WILLARD A. MORAIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,353,100 Wales Sept. 14, 19202,178,310 Pateras Pescara Oct. 31, 1939 2,189,497 Pateras Pescara Feb.6, 1940 2,222,260 Janicke Nov. 19, 1940

